Cannot scrub server_name

I cannot seem to scrub the server_name field from events no matter how hard I try.

I’ve gone to Project settings > Tags and deleted the Server entry so that it no longer appears in the list of tags (this did not delete the data from the events).
I’ve set server_name, serverName, and Server in my sensitive fields list in project settings.
I’ve explicitly set serverName on my config to ‘redacted’ and server_name in my event tags to ‘redacted’.

Despite all of this server_name continues to be populated with the result of hostname on my machine. Any help?

(I’m using the Node.js SDK raven npm module FWIW)

servername worked for me.